After I remove the droppings and insulation that I can realistically remove manually, it's time to fog. There's no way to manually remove all rat droppings, and of course one cannot remove urine and fur grease. Some of the droppings are down walls. Many are basically embedded in insulation.
Telnet is a user command and an underlying TCP/IP protocol for accessing remote computers. Through Telnet, an administrator or another user can access someone else's computer remotely.
Telnet even predates internetworking and the modern IP packet and TCP transport layers. The TELNET protocol provides a standardized interface, through which a program on one host (the TELNET client) may access the resources of another host (the TELNET server) as though the client were a local terminal connected to the server.